Reduced mind wandering in patients with Parkinson's disease

Mind-wandering in Parkinson's disease hallucinations reflects primary visual and default network coupling

“…We followed this interaction with tests of simple effects to determine whether the groups differed in their response frequencies at any Level apart from Level 4, which we showed in our focused analysis above. In addition, all groups showed an increased tendency towards mind-wandering on longer trials (See Supplementary material and Figure S1 for analyses and results), replicating previous studies using the task (Geffen et al, 2017;O'Callaghan et al, 2019).…”

“…Behavioural analysis of the thought-sampling task revealed that mind-wandering frequency was significantly higher in the hallucinating patient group compared to the non-hallucinating patient group; no significant differences were found between the hallucinating patient group and controls. In contrast, the frequency of mind-wandering was lower in non-hallucinating patients relative to controls, replicating findings from an independent Parkinson's disease cohort tested on the same task (Geffen et al, 2017).…”

“…Non-hallucinators exhibited reduced mind-wandering compared to controls, accompanied by a negative association between mind-wandering frequency and primary visual-dorsal default network coupling. In light of the present evidence, we suggest two distinct trajectories in Parkinson's disease: in Parkinson's disease with hallucinations, relative to impaired sensory and attentional abilities, forms of internally generated mental imagery are relatively better preserved, which leads them to dominate perception -a process underpinned by increased primary visual-default network coupling; in Parkinson's disease without hallucinations, such forms of cognition and the supporting neural circuity are compromised, consistent with a more generic course seen in ageing (Maillet and Schacter, 2016) and exacerbated in several neurodegenerative diseases (Geffen et al, 2017;Gyurkovics et al, 2018;O'Callaghan et al, 2019).…”

Mind-wandering in Parkinson’s disease hallucinations reflects primary visual and default network coupling

“…The Level x Group interaction was significant [F(6,300) = 3.06, p < 0.01]. We followed this interaction with tests of simple effects to determine whether the groups differed in their response frequencies at any Level apart from Level 4, which we showed in our Figure S1 for analyses and results), replicating previous studies using the task (Geffen et al, 2017;O'Callaghan et al, 2019).…”

“…Our generic course seen in ageing (Maillet and Schacter, 2016) and exacerbated in several neurodegenerative diseases (Geffen et al, 2017;Gyurkovics et al, 2018;O'Callaghan et al, 2019).…”